Cisco 3845 - Security Bundle Router Quick Start Manual page 18

A Cisco 3800 series router with a DC-input power supply requires copper wire for the power connections. Table 1 and Table 2
summarize the DC wiring requirements.
If you connect dual DC power sources to a Cisco 3825 router, both sources must be the same polarity and voltage.
For a Cisco 3845 router, the safety ground wire connection must be at the same potential as the 0 V (return) connection.
Table 1 DC Wiring Requirements for Cisco 3825 Routers
1
DC Input
24–36 VDC, 12 A, positive or
negative, single source or dual sources
36–60 VDC, 8 A, positive or negative,
single source or dual sources
1. The input voltage tolerance limits for DC power are 18 and 72 VDC.
Table 2 DC Wiring Requirements for Cisco 3845 Routers
1
DC Input
24–36 V, 19 A, positive or negative,
single source or dual sources
36–60 V, 13 A, positive or negative,
single source or dual sources
1. The input voltage tolerance limits for DC power are 18 and 72 VDC.
Wiring Procedure for DC Input
To connect the router to a DC power source, perform the following steps:
Remove power from the DC circuit. To ensure that power is removed from the DC circuit, locate the circuit breaker for
Step 1
the DC circuit, switch the circuit breaker to the OFF position, and tape the circuit-breaker switch in the OFF position.
Warning Before performing any of the following procedures, ensure that power is removed from the DC circuit.
Statement 1003
Tip Secure all power cabling when installing this unit, to avoid disturbing field-wiring connections.
Warning When stranded wiring is required, use approved wiring terminations, such as closed-loop or spade-type with
upturned lugs. These terminations should be the appropriate size for the wires and should clamp both the
insulation and conductor. Statement 1002
Strip the wires to the appropriate length for the terminals. The strip length is 3/16 to 1/4 inch (5 to 6 mm) for Amp/Tyco
Step 2
number 32957 terminals and 5/16 to 3/8 inch (8 to 9 mm) for Amp/Tyco number 34852 terminals.
Step 3 Crimp the terminals onto the DC power input and safety ground wires.
Step 4 Remove the plastic safety covers from the terminal block. Save the covers for reinstallation after you finish wiring.
18
Safety Ground Wire
DC Input Wire Size Size
2
AWG 14 (2.0 mm ) AWG 14 (2.0 mm
minimum
DC Input Safety Ground
Wire Size Wire Size
AWG 12 AWG 12 (3.0 mm
2
(3.0 mm ) minimum
AWG 12 or 14 AWG 12 (3.0 mm
2
(3.0 or 2.0 mm ) minimum
Wire Terminal (Lug)
2
), Amp/Type No. 32957
or equivalent
Wire Terminal (Lug)
2
), Amp/Tyco No. 34852 or
equivalent
2
), For AWG 12: Amp/Tyco
No. 34852 or equivalent
For AWG 14: Amp/Tyco
No. 32957 or equivalent
Overcurrent
Protection
20 A maximum
Overcurrent
Protection
30 A
20 - 30 A